1. Field of the Invention
The present invention relates to a device for grinding the edges of the core of a track slider.
2. Description of the Prior Art
Track sliders are incorporated in magnetic heads for use with magnetic discs for computers or video tapes, and serve as a transducer for converting an electric signal into a magnetic signal or vice versa. As illustrated in FIGS. 1 and 2 of the accompanying drawings, such a magnetic head has a track slider 1 as a major component. The track slider 1 is small in size and made of ferrite. The track slider 1 has a smooth tracing surface 2 and a positioning groove 3 defined in a surface remote from the tracing surface 2. A core 4 is integrally formed with one side of the tracing surface 2. The core 4 has a C shape as seen in side elevation and has a tip end defining a gap 5 and fixed by a body of melted glass 6 near the tracing surface 2. The core 4 has dimensions as indicated in FIGS. 1 and 2.
The core 4 includes a portion 7 in the form of a quadrangular prism serving as a coil support portion for supporting a coil 8. The coil 8 is composed of an enameled wire having turns in the range of from 10 to 25 around the coil support portion 7 for converting an electric signal into a magnetic signal or vice versa.
The coil support portion 7 is integrally formed when the ferrite core is fired or sintered, and hence has sharp edges having an angle of 90.degree.. If the coil 8 were directly wound around the coil support portion 7, the insulating enamel coating would be peeled off, resuling in an insulation failure and a short circuit. Therefore, suitable insulation would have to be incoporated.
To avoid the above shortcoming, it has been customary practice to grind off edges 7a with a strip of sanding paper to form a suitable round surface. However, since the sanding operation has been manually effected, the efficiency is low, sanded surfaces have not been even, and the core 4 has sometimes been broken in the grinding operation.
There have been practiced alternatives instead of the above grinding process. One effort has been to wind an insulating tape around the core 4. Another attempt has been to fit a C-shaped insulating ring over the core 4. If the insulation is attached to the coil support portion, then magnetic coupling between the core 4 and the coil 8 is lowered and weak signals cannot be well converted. Therefore, it has been found that the winding of the coil 8 directly around the core 4 is most effective.